Season the filet mignon steaks with salt and black pepper. Let them sit at room temperature for 15 minutes while you prepare the sauce.
In a large skillet, melt 2 tablespoons of butter over medium heat. Add the minced garlic and chopped shallot and sauté until fragrant, about 2 minutes.
Pour in the white wine and lobster stock, then allow it to simmer for about 5 minutes until it reduces slightly.
Add the chopped lobster meat and shrimp into the skillet. Cook for an additional 3-4 minutes until the shrimp turn pink and opaque.
Reduce the heat to low and slowly whisk in the heavy cream. Continue to cook for another 5-7 minutes until the sauce thickens. Season with salt and pepper to taste. Remove from heat and keep warm.
While the sauce is thickening, heat another skillet over high heat. Add 2 tablespoons of butter and let it melt. Once the butter is sizzling, add the filet mignon steaks.
Sear the steaks for 4-5 minutes on each side for medium-rare, adjusting the time for your desired doneness. Use tongs to turn the steaks.
Once cooked, remove the steaks from the skillet and let them rest for 5 minutes.
To serve, place the filet mignon on each plate and generously spoon the shrimp and lobster cream sauce over the top. Garnish with freshly chopped parsley.